The latest mobile app version, 5.110.4.250331429, keeps popping a stupid notification to set up VPN. I have VPN shut off as I have another VPN service. I even have notifications shut off and still getting it. The latest Norton versions for both PC and mobile are buggy and lack expected features. Get you act together and fix this.
Try setting up the VPN and turn it on for a few seconds. Then turn it off and forget about it. See if that stops the messages.